MORPHOLOGY/SYNTAX: a term which is used for the passive of prepositional
verbs. Prepositional verbs are intransitive verbs followed by a prepositional phrase which permits
Preposition Stranding. This means that the passive construction can treat the NP complement of the preposition as a kind of direct object and promote it to subject. Compare the following examples from English:

(i) Someone has slept in my bed
My bed has been slept in (by someone)
(ii) Someone is pointing at me
I don't like being pointed at
(iii) Many people are sleeping in London
* London is being slept in (by many people)